Are you looking for info on them as totem animals and guides, or just the bird itself?
From what I've gleaned from a quick google search, in Western cultures, the bird is often viewed as an ill omen. Eastern cultures see them as a more positive omen. They are also often associated with magic, divination, and prophecy.
I've added a few links below for you to look over. They have lore, associations, info on them as totems and spiritual guides, the bird in folklore, etc. Hopefully this helps!